The best amusement machine for 8th graders to buy is a video game console. Video game consoles offer a wide variety of games that cater to different interests and skill levels. They are also more affordable than high-end arcade machines and provide a better value for money. According to the Entertainment Software Association (ESA), the average age of a video game player in the United States is 34, but the majority of players are under the age of 18. This indicates that video games are a popular choice among younger demographics, including 8th graders. Additionally, video game consoles are designed to be user-friendly and come with parental controls, which can help parents monitor their children's gaming habits.